1. Field of the Invention
The present invention relates to an image forming apparatus. More particularly, the present invention relates to a method and an apparatus for indicating the time to replace consumables in an image forming apparatus by receiving the current date and the critical time for replacing consumables from a host and comparing the time to replace with the current date and critical time.
2. Description of the Related Art
FIG. 1 is a block diagram of a conventional image forming system. The image forming system comprises a host 100 and an image forming apparatus 200. The host 100 includes an application program 110, a graphics device interface (GDI) 120, an image forming apparatus driver 130, a user interface 140, and a spooler 150. The image forming apparatus 200, typically a printer, comprises a video controller 210, an engine controller 220, and a battery 230. The video controller 210 includes a non-volatile random access memory (NVRAM) 212 and a real-time clock (RTC) 214.
The application program 110 generates an object output using the image forming apparatus 200 and edits the object. The GDI 120, residing in an operating system of the host, receives the object generated at the application program 110 and transmits it to the image forming apparatus driver 130, and generates a command related to the object the image forming apparatus driver 130 is requesting.
The image forming apparatus driver 130 generates a command interpretable by the image forming apparatus 200. The user interface 140 for the image forming apparatus driver 130 provides environmental variables in order for the image forming apparatus driver 130 to generate the command. The spooler 150, a program residing in the operating system of the host, transmits the command generated by the image forming apparatus driver 120 to a physical input/output device (not shown) connected to the image forming apparatus 200.
The video controller 210 interprets the command generated by the image forming apparatus driver 130 and bitmaps an image, and then transmits the bitmapped image to the engine controller 220. The engine controller 220 transmits the bitmap image generated by the video controller 210 to printing media (not shown).
During printing, as shown above, consumables in the image forming apparatus 200 are used. The consumables are, for example, a developer, ink, and a fixer. Such consumables need to be replaced after a predetermined time regardless of how often printing was performed. For example, the developer should be replaced after a year.
The conventional image forming apparatus 200 determines the time to replace the consumables using the NVRAM 212, the RTC 214, and the battery 230. In other words, the critical time, which is the time when the consumables should be replaced, is stored inside the NVRAM 212. The critical time may be initialized when the product is produced and renewed when the consumables are replaced. The RTC 214 provides the current time using the power supplied from the battery 230. That is, the current time received from the RTC 214 is compared to the critical time stored in the NVRAM 212. If the current time is the same as or greater than the critical time, information that the consumables need to be replaced is indicated on an indicator (not shown) of the image forming apparatus 200, for example, a panel.
As described-above, the RTC 214 and the battery 230 are needed in order to indicate the time to replace the consumables on the panel. However, a low cost image forming apparatus may not include the RTC 214 and the battery 230. In this case, the user cannot be informed of the time to replace the consumables.
Japanese Published Application No. 2000-71581 discloses a printing system that predicts and indicates the date to replace a consumable by measuring the consuming rate of the consumable article. However, it does not disclose a method of indicating the time to replace the consumable regardless of how frequently the consumable article was used.